# Drug poisonings following bariatric surgery: Case series report

## TL;DR

Bariatric surgery patients are at increased risk of drug-related deaths due to altered medication absorption and misuse of prescription drugs.

## Contribution

This study reports 18 cases of drug poisonings in bariatric surgery patients and highlights the role of altered pharmacokinetics and comorbidities.

## Key findings

- Opioids were detected in nearly all cases and were frequently linked to death.
- Unprescribed medications were commonly found in post-mortem analyses.
- Mental health and chronic pain were common comorbidities, with one-third of deaths classified as suicide.

## Abstract

Bariatric surgery alters gastrointestinal anatomy and physiology, which likely impacts upon oral medication absorption. Drug‐ and alcohol‐related deaths in this population are being increasingly reported; however, toxicological detail is lacking. Using data reported to the National Programme on Substance Use Mortality, we identified 18 deaths in people who had previously undergone bariatric surgery. Opioids were detected in almost all cases and were frequently implicated in causing death. Multiple medications were detected at post‐mortem in every case and often included medications that the deceased was not actively prescribed. Mental health conditions and chronic pain were commonly listed comorbidities and one‐third of deaths were deemed suicide. Illicit drug and alcohol use was rare, highlighting a distinct vulnerability to prescription medication harms. Our findings emphasize a need to understand how bariatric surgery alters pharmacokinetics and for integrated, multidisciplinary aftercare, therapeutic drug monitoring and tailored education of safe medication use in bariatric surgery patients.